fix(webpack): allow transpilation of .cjs files

[gnuletik]

Types of changes

• Bug fix (a non-breaking change which fixes an issue)
• New feature (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Description

When trying to transpile a file from node_modules through the build.transpile property, files ending with .cjs were previously ignored.

This PR fixes it.

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly. (PR: #)
• I have added tests to cover my changes (if not applicable, please state why)
• All new and existing tests are passing.

[gnuletik]

@danielroe thanks for the approval !

For anyone interested in this feature before it gets merged, you can extend your webpack config like this :

// nuxt.config.ts
export default {
// ...
  build: {
    extend (config: any, { isDev, isLegacy }: any) {
      // https://github.com/nuxt/nuxt.js/pull/10240
      const babelConfig = {
        configFile: false,
        babelrc: false,
        cacheDirectory: true,
        plugins: [
          '@nuxtjs/composition-api/dist/babel-plugin'
        ],
        presets: [
          ['@nuxt/babel-preset-app/src/index.js', {
            corejs: { version: 3 },
            jsx: { compositionAPI: true }
          }]
        ],
        envName: 'client'
      }

      if (!isDev && isLegacy) {
        config.module.rules.push({
          test: /\.c?jsx?$/i,
          exclude: (file: string) => {
            file = file.split(/node_modules(.*)/)[1]

            // not exclude files outside node_modules
            if (!file) {
              return false
            }

            const cjsTranspile = [/defu/]

            // item in transpile can be string or regex object
            return !cjsTranspile.some(module => module.test(file))
          },
          loader: 'babel-loader',
          options: babelConfig
        })
      }
   }
// ...
}

You can edit cjsTranspile to update the list of modules to transpile.

[pi0]

Thank you so much for making this PR @gnuletik ❤️ I'm closing it in favor of #10340 which has updated tests.

[kyumoon]

@gnuletik thanks for your config code
in my case, i had to change the test regex to test: /\.cjsx?$/i,